1. Field of the Invention
This invention relates generally to an underwater tunnel system for vehicular traffic flow, including rail, automobile and truck traffic and, more specifically, to a submerged floating tunnel system of modular construction which utilizes submarine technology to provide specific and adjustable buoyancy capabilities.
2. Description of the Prior Art
The prior art, comprising known or existing techniques for connecting two land masses, includes bridges and tunnels.
As a means of traversing a body of water between two land masses, bridge construction presents several major problems. Because bridge construction is performed substantially (about 95%) on site, delays and cost overruns are common, being subject to seasonal changes and inclement weather. In addition, the average construction time (including design) of a conventional bridge is five to seven years. Once in place, conventional bridges possess several characteristics which also present difficulty. Exposure to weather and the elements requires constant examination and continuous maintenance efforts. In addition, the same weather factors which hinder construction and shorten the life span of the resulting structure also adversely affect traffic conditions. Finally, conventional bridges can have significant environmental impact as well as degrading the scenery or skyline of the surrounding land mass areas.
Currently, underwater tunnels also contain serious flaws and weaknesses in both their design and technique of construction. Conventional tunnels require extensive boring beneath the seabed, riverbed, or the like. This is a process which results in both substantially lengthening the construction period and substantially increasing costs. Furthermore, the extensive boring required in the construction of conventional tunnels also can have negative effects on the surrounding marine environment.
While submerged and prefabricated tunnels already exist, these systems are not without flaws. Through this invention, both existing tunnel technology and design will be improved upon substantially. Presently, submerged tunnels utilize concrete tubes which, although about 60% prefabricated, require substantial on-site work. The prefabricated tubes used in concrete tunnels employ relatively short 300 foot sections. In order to build and install a concrete submerged tunnel on the floor of the body of water being traversed, additional concrete pours (above the waterline) are required to create the negative buoyancy necessary to submerge and lower these tube sections under the control of barge cranes. Extensive dredging is also required in order to produce the level of prescribed foundation to effectively join these tube sections together.
Finally, and most importantly, once a concrete tunnel of known design, is permanently weighted down with additional concrete in order to overcome positive buoyancy, repairs to the tunnel become difficult. Due to the permanent nature of the structure, maintenance and repair work can only be accomplished on site and underwater.
Numerous patents exist which are representative of a variety of fields of invention which must be considered when considering solutions to the problem being addressed by the inventors.
For example, U.S. Pat. No. 3,849,821 issued Nov. 26, 1974 to Arild et al. and U.S. Pat. No. 3,478,521 issued Nov. 18, 1969 to Petrik, disclose submerged tunnel bridges assembled underwater from prefabricated concrete modules.
U.S. Pat. No. 4,406,151 issued Sep. 27, 1983 to Simonsen et al., U.S. Pat. No. 4,165,196 issued Aug. 21, 1979 to Serrano, and U.S. Pat. No. 3,893,304 issued Jul. 8, 1975 to Pochitaloff-Huvale all disclose the fabrication of underwater structures.
U.S. Pat. No. 5,362,921 issued Nov. 8, 1994 to Birkelund et al., U.S. Pat. No. 4,892,442 issued Jan. 9, 1990 to Shoffner, U.S. Pat. No. 2,770,950 issued Nov. 20, 1956 to Collins, and U.S. Pat. No. 244,752 issued Jul. 26, 1881 to Hunter et al. all disclose various underwater cable constructions and techniques for their installation.
Numerous U.S. patents disclose the laying of underwater pipeline, of which the following are exemplary:
In a similar fashion, the following U.S. patents disclose methods and apparatus for joining pipe sections underwater:
It was in light of the foregoing and the inventors"" expertise in submarine construction and design that the present invention was conceived and has now been reduced to practice.
The present invention relates to an underwater tunnel system for vehicular, including rail, traffic connecting the shores of opposed land masses separated by a body of water. The invention draws heavily from submarine manufacturing and modular construction technology. It is environmentally benign and will not adversely dominate the skyline of the surrounding region. The system of the invention requires minimal, if any, dredging to insure its substantially level installation. A compensating ducting, piping and valve system is utilized for initial tunnel submergence during construction and to provide dynamic stability subsequently during operation. Part of the ducting system utilized during submergence operations is also subsequently used for ventilation air flow throughout the tunnel system during operation. During operation, fresh air is introduced from both shores into the tunnel system and exhaust air may be selectively discharged at both shores or from the tunnel system at locations distant from both shores.
It will be understood that the specific design parameters for constructing a Transportation Underwater Tunnel System (TUTS) in accordance with the present invention will vary with each specific project location. For example, it will be necessary for the project engineer to calculate and design the length of the tunnel and its desired width to accommodate optimum traffic conditions. Furthermore, the project engineer will have to determine the desired depth of the tunnel dependent upon the type of ship channel depth constraints. A tunnel marker buoy may be used to indicate the location of the inclined tunnel sections adjacent to both land masses. This tunnel marker will provide guidance for marine vessels passing above the tunnel, through the body of water, taking into account the tidal changes.
As stated above, each of these specific design parameters, as well as others, may be different for each individual project. However, one ordinarily skilled and reasonably competent in this particular art would readily understand how this design functions and could construct a Transportation Underwater Tunnel System in accordance with the present invention. According to the invention, there are three (3) basic tunnel configuration options or combinations that can be constructed and installed based upon tunnel size (number of traffic lanes), geographical and geological conditions and the marine environment to properly locate a specific tunnel configuration, as follows:
Type Ixe2x80x94Shallow Water Elongated Tunnel (approximate depth of 40 feet to 60 feet)
Type IIxe2x80x94Shallow Depth Cylindrical or Elongated Tunnel (approximate depth of 50 feet to 100 feet)
Type IIIxe2x80x94Open Depth Cylindrical Tunnel (approximate depth of 70 feet or greater)
In each instance, the depth indicated is the depth to the cylinder top centerline of the cylinder at mean low water level.
The following are typical characteristics of the Type I (Shallow Water Elongated) tunnel configuration:
(1) approximate depth: 40 feet to 60 feet
(2) extensive dredging
(3) concrete support pads to set designated depth
(4) controlled buoyancy to position cylinders only (lower to depth)
(5) temporary and permanent weighting (lead/concrete) for stability
(6) external and/or internal tank ballast/compensating configuration
(7) double hull plating topside configuration (optional)
(8) no active operational buoyancy systems.
The following are typical characteristics of the Type II (Shallow-Depth Cylindrical or Elongated) tunnel configuration:
(1) approximate depth: 50 feet to 100 feet
(2) limited dredging
(3) concrete support pads to set designated depth
(4) limited controlled buoyancy operations (less than about 25%)
(5) temporary and permanent weighting, (lead/concrete) for stability
(6) external and/or internal tank ballast/compensating configuration
(7) double hull plating topside configuration (optional)
(8) restricted active operational buoyancy systems.
The following are typical characteristics of the Type III (Open-Depth Cylindrical) tunnel configuration:
(1) approximate depth: 70 feet to 150 feet
(2) minimum dredging
(3) land transition set designated depth of inclined tubular tunnel sections
(4) maintains prescribed depth tolerance by using controlled buoyancy system equipment operation
(5) permanent weighting (lead/concrete) for buoyancy stability and depth control requirements
(6) external and/or internal tank ballast/compensating configuration
(7) full double hull configuration (optional)
(8) controlled buoyancy/depth monitored cylinder alignment/structural integrity.
Accordingly, a primary feature of the present invention is the provision of an improved system for connecting two land masses which are separated by a body of water.
Another feature of the present invention is the provision of such a system which will connect two land masses, and which is substantially prefabricated, at least about 85% complete, and which is of modular construction to thereby reduce costs and time of installation.
A further feature of the present invention is the provision of such a modular construction technique according to which prefabricated tubular tunnel sections are fabricated at an off-site location, then transported to the site already equipped with roadways, tank structure, piping, ventilation, electrical and auxiliary support subsystems in place except for the predetermined join areas for these subsystems.
Still another feature of the invention is to provide such a structure for traversing a body of water between two land masses which is 85% prefabricated at a separately controlled facility and will not subject the construction process to the delays resulting from inclement weather.
Yet a further feature of the present invention is to provide such a structure for traversing a body of water between two land masses which is 85% prefabricated at a separate facility and will significantly reduce total construction and installation time, including design because of its simplicity and repetitive end product definition.
Yet another feature of the invention is to provide such a structure for traversing a body of water between two land masses which is not open and exposed to the surface elements and to adverse weather conditions.
Still a further feature of the present invention is to provide such an underwater tunnel system which utilizes a steel hull similar to that utilized in the construction of submarines and which will provide a proven ability to withstand the surface elements and marine environmental elements.
Yet a further feature of the present invention is to provide such an underwater tunnel system designed to have a life span of no less than at least 75 to 100 years.
Still another feature of the present invention is the provision of such an underwater tunnel system which enables the traversing of a body of water between two land masses while not adversely dominating the skyline and without being detrimental to the surrounding scenery and environment.
Still a further feature of the present invention is the provision of such an underwater tunnel system which does not require extensive dredging of the seabed or riverbed area subterrain in order to properly construct and install it on a somewhat level setting.
Another feature of the present invention is the provision of such an underwater tunnel system which utilizes automatically controlled and adjustable buoyancy conditions at various depths. To this end, a compensating piping and valve system will be utilized for the initial tunnel submergence during construction and subsequently during operation, will provide dynamic stability to accommodate substantial weight changes.
Yet another feature of the present invention is the provision of such an underwater tunnel system with an internal tank system which has the capability to be utilized for tunnel buoyancy operations for tunnel submergence until structurally secured.
Yet another feature of the present invention is the provision of such an underwater tunnel system which enables a conversion of a major portion of the tunnel internal tank system to function as the internal ducting system for air flow throughout the tunnel environment during the operational phase of the tunnel.
Yet another feature of the present invention is the provision of such an underwater tunnel system which, by reason of its modular construction configuration, can be repaired if required by raising only the affected section of the tunnel rather than attempting to perform any major repairs underwater.